1. Field of the Invention
The present invention relates to a film molded casing to which coloring or display can be easily applied by insert molding a transparent resin into a film molded member that has been subjected to coloring or display.
2. Description of the Related Art
In recent years, with the diversification of their functions, electronic devices, in particular, devices in which illumination display of the operational conditions of inner circuitry is performed, has been given various functional displays, and various patterns have been provided thereon in order to discriminate them from other products.
For a casing of such electronic devices, a resin molded product that has been formed by injection molding is used. The surface of this type of casing assumes a resin color by coloring, or a color by painting. When displaying characters or a symbol, such as the name of a company or a logo, on the casing surface, the display has usually been performed by methods as follows: 1) rugged display by molding, 2) insert molding of a plate with a pattern previously printed thereon into the casing surface when the casing is molded, 3) printing by hot stamping, or 4) silk printing onto the casing surface.
Meanwhile, in any of these coloring and display methods with respect to the casing, it is necessary to form a display window that allows illumination display elements in the casing to be visually identified from the outside. Therefore, a window hole has been formed in the casing, and a transparent resin cover which is a separate member has been fitted to the window hole.
FIGS. 3A to 3C show an example of the extending portion of a conventional CF (Compact Flash™) card. FIG. 3A is a plan view of the extending portion. FIGS. 3B and 3C are sectional views taken along the line A-A′ in FIG. 3A, and these figures are each a process diagram illustrating an LED (Light-Emitting Diode) lens assembly process. Here, FIGS. 3B and 3C, respectively, show the extending portion before and after the LED lens assembly.
As shown in FIG. 3A, a casing 51 is formed by molding such as injection molding using a translucent or opaque resin material depending on the color of the resin itself, or coloring. There are provided rectangular window holes 51-1 penetrating the casing. As shown in FIG. 3B, an LED lens 52 is fitted into each of the window holes 15-1 of the casing 51. The fitting position of each of the LED lenses 52 relative to the casing 51 is adjusted so that the outside surface of each of the LED lenses 52 and that of the casing 51 become mutually flush, as shown in FIG. 3C, which illustrates a state of the LED lens 52 after assembling. As a result, each of the LED lenses 52 is disposed so as to oppose an LED 10 on a substrate 11.
In this manufacturing method for the casing, an assembly process between the LED lenses and casing is additionally needed. This unfavorably requires correspondingly more time and labor, resulting in an increased manufacturing cost of the casing.
The above-described conventional example involves another problem in that lenses molded separately from the main body using a resin with a high light-permeability must be each built into the light-emitting portion of the LED.
Under such circumstances, in order to solve some of the above-described problems, a technique to perform the formation of display windows concurrently with the molding of a casing by insert molding, has been proposed (see, for example, Japanese Unexamined Patent Application Publication No. 2000-318052).
According to this technique, a casing is formed by air-pressure forming a synthetic resin sheet having a transparent window portion and another opaquely colored and displayed portion to deeply draw the sheet, then insert molding the sheet after filling a transparent synthetic resin sheet on the rear surface of the sheet, and integrally forming a display window having the window portion.
In general, for a casing of the above-described conventional electronic device, a resin molded product is used in many cases. However, the color tone and feeling of the surface of this casing depend on a resin material for molding or a painting material for painting the surface after molding.
Also, there is a problem that a poor outer appearance such as a surface sink (i.e., an uneven thickness structure such as warp) or weld (due to poor transmission of pressure in a mold) may occur depending on a molding condition. When displaying characters or a symbol such as the company name on the surface of a resin molded product, rugged display has been provided by molding, or printing display has been performed on the outer surface of the resin molded product using silk printing method or the like. However, it is difficult to read rugged characters because the rugged characters are of the same color as that of the resin. Furthermore, a long-term use of the resin molded product accumulates dust in rugged portions, and/or causes peeling or the like of printed portions.
The light-emitting portions of LEDs provided on the casing of a conventional electronic devices have been arranged so that light-emitting states of the LEDs can be visually identified from the product surface side, by providing window holes in the casing body, and building, into each of the window holes, a lens component molded separately from the casing using a resin having a high light-permeability. In this case, it has been necessary to produce a mold for the LED lens besides a mold for the casing, and perform molding for the casing and LED lens separately from each other.
Furthermore, in manufacturing, there has been a process to build LED lenses into the casing, which has incurred the risk of omitting to build LED lenses into the casing and/or causing failures of components.